1. Field of the Invention
The present invention relates to a charging generator for a car having a drainage and rust-resistance structure.
2. Description of the Prior Art
In the conventional generator of this kind, a hole is formed in the lower side of a rear bracket to fit a drain hose in order to effectively discharge undesirable substance such as salt water, mud water etc. entering into the rear bracket to the outside.
In the fitting of the drain hose, the following problems arise: (1) a machining operation is required to form a drain hole, (2) an accurate dimension for the drain hose is required whereby material used is limited, and (3) much labor time is required in the assembling operation in comparison with that for the other parts.
The structure of the conventional charging generator will be described with reference to FIG. 1. In the FIG. 1, the reference numeral (1) designates the rear bracket of a charging generator for a car, (1a) designates a ventilation hole for cooling formed in the rear bracket, (1b) designates a drain hole formed in the lower wall by machining operation and (2) designates a drain hose fitted to the drain hole.
In the conventional structure, undesirable substance such as salt water, mud water enters from the ventilation hole for cooling (1a) to the inside of the rear bracket to deposit on the lower wall. It is, therefore, necessary to form a drain hole (1b) by machining operation in order to discharge the undesirable substance outside. Further, it is necessary to fit a drain hose (2) in order to discharge it more effectively.
Various methods can be considered to fit the drain hose. In the first method, the drain hose (2) is forcibly fit to the drain hole (1b) to fix it. This method has advantages that an accurate dimensions are required for both the fitting parts and an additional operation of forcibly fitting is required.
In the second method, a drain hose (2) made of a soft rubber is inserted into the drain hole (1b). In this case, the material used is limited, the cost of the material is high and it is difficult to mechanize the assembling operation.
Where an electrical device is placed at the lower portion of the bracket, undesirable solidified substance of salt water, mud water etc. is deposited between the electric device and the inner wall of the rear bracket (1). Stray current corrosion caused by the deposition sometimes resulted in faulty generation of current.